能量水平对20～30 kg羔羊生长性能、能量和氮表观消化率的影响

本试验旨在研究不同能量水平对道寒杂交羔羊生长性能、能量和氮表观消化率的影响,为肉用羔羊配制适宜营养水平的日粮提供依据。选用体重20 kg左右的道寒杂交断奶公羔48只,随机分为3组,每组4个重复,每个重复4只。以NRC(2007)营养需要量参数为依据,配制不同代谢能水平(10.12、11.11、12.05 MJ/kg)日粮,可消化蛋白(11%)、钙和磷水平一致。试验预试期15 d,正试期50 d。当其中1组平均体重达到30 kg时,每组取6只,采用全收粪法收集粪样,测定能量和氮表观消化率。结果表明:羔羊体重、日增重、采食量均随能量水平的增加而提高,其中高能组极显著高于低能组(P0.01),显著高于中能组(P0.05),中能组显著高于低能组(P0.05);高能组日粮能量表观消化率显著高于低能组和中能组(P0.05),低能组与中能组间差异不显著(P0.05);高能组和中能组的日粮氮表观消化率极显著高于低能组(P0.01),高能组与中组间差异不显著(P0.05)。综上所述,日粮能量水平影响羔羊能量和蛋白的消化利用及生长发育,当20~30 kg羔羊日粮含11%可消化蛋白,代谢能为12 MJ/kg时羔羊生长性能、能量和蛋白利用率最佳。

Influence of Energy Level on Growth Performance and Apparent Digestibility of Energy and Protein of 20-30 kg Lambs

This experiment was conducted to investigate the effects of dietary energy level on growth performance and apparent digestibility of energy and protein of Dorset×thin-tailed Han sheep crossbred lambs, to provide a guidance for scientific feeding meat lambs. A total of 48 lambs(approximate weight of 20 kg) were randomly divided into 3 groups, each group comprises 4 replicates, In each replicate, 4 lambs were used. According to NRC(2007), experimental lambs were fed diets with consistent DIP(11%), calcium and phosphorus levels, but with different ME levels(10.12,11.11 and 12.05 MJ/kg, respectively). 6 lambs in each group were selected for a digestion and metabolism trial when the lambs in one of groups reached 30 kg of average body weight. The results showed that body weight, daily gain and feed intake in group Ⅰ were significantly higher than those group Ⅰ(P<0.001) and groupⅠ(P<0.05), groupⅠ were significantly higher than those groupⅠ(P<0.05). Apparent digestibility of Energy in groupⅠ were significantly higher than those of Ⅰand groupⅠ(P<0.05), but had no significant difference between groupⅠ and Ⅰ(P>0.05). Apparent digestibility of Protein in groupⅠ and Ⅰ were significantly higher than those ofⅠgroup(P<0.001), but had no significant difference between groupⅠand Ⅰ(P>0.05). In conclusion, the dietary energy level effected the digestion of energy and protein, as well as the growth of lambs. It is the best for 20-30 kg meat lamb fed dietary digestible protein level at 11%, metabolic energy at 12 MJ/kg.